1. Field of The Invention
The subject invention relates to displaying images having a certain aspect ratio on display screens having a different aspect ratio.
2. Description of The Related Art
With the advent of widescreen displays in which the display screen has an aspect ratio of 16:9, a problem has arisen when images having an aspect ratio of 4:3 are displayed on the screen. In particular, as shown in FIG. 1A, the 4:3 aspect ratio image 1 is displayed on the screen with vertical black bands 2 and 3. Since at the present time, most video signals have the 4:3 aspect ratio, "burn in" may occur on the display screen where the screen phosphors are aged only in the area where the image is displayed. This then leads to distortions when viewing a true 16:9 image on the display.
Similarly, motion pictures are generally shot in a 16:9 aspect ratio. However, when that picture is reformatted for the standard 4:3 aspect ratio, information is lost. Now many motion picture studios release these motion pictures also in "letterbox" format in which the 16:9 image is compressed such that it fits the 4:3 aspect ratio. This is shown in FIG. 1B where the 16:9 image 4 appears between two horizontal black bands 5 and 6.
In addition to being detrimental to the display, the appearance of these vertical or horizontal black bands is disturbing to the user of the display and detracts from the viewing experience.
Conversion circuitry is know that is capable of expanding a displayed image both horizontally and vertically in order to eliminate these black bands. However, it is up to the user to decide when and which of these conversions is to be used.